Of the world's 4 million patients who suffer from Parkinson's disease, nearly 1.7 million are in China, a survey by Chinese experts shows.

The survey, published in the latest issue of the medical journal Lancet, was conducted by Zhang Zhenxin, an expert at the Beijing Union Medical College Hospital, Xinhua reported Thursday.

Zhang found the incidence of Parkinson's disease to be 1.7 percent among Chinese men over 60 years of age, and 1.6 percent for women, compared to the world average of 1 percent.

Many patients questioned for the survey said they had never received treatment of any kind, the report said.

Pakinson's disease is a progressive disorder of the nervous system occurring most often after the age of 50 and characterized by muscular rigidity, tremors, and impaired motor control.

Copyright 2006 by United Press International